Light emitting module and lighting apparatus having the same

ABSTRACT

A light emitting module includes a printed circuit board (PCB) and first through m-th lighting blocks of optical semiconductor devices (‘m’ is an integer greater than one). The PCB has wiring patterns electrically connecting optical semiconductor devices. The first through the m-th lighting blocks are disposed on the PCB and configured to generate light. Each of the first through the m-th lighting blocks includes first through n-th lighting groups (each block includes at least one group), each of which includes optical semiconductor devices disposed on the PCB. Electric currents configured to flow through each of the first through n-th lighting group is substantially the same. The PCB includes a pair of bodies spaced apart from each other and ‘m’ number of elbows connecting the pair of bodies, and each elbow respectively corresponds to the first through the m-th lighting blocks.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.14/101,654, filed on Dec. 10, 2013, and claims priority from and thebenefit of Korean Patent Application Nos. 10-2013-0124851, filed on Oct.18, 2013, and 10-2013-0124859, filed on Oct. 18, 2013, which are herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

1. Field

Exemplary embodiments of the present invention relate to a lightemitting module and a lighting apparatus having the light emittingmodule. More particularly, exemplary embodiments of the presentinvention relate to a light emitting module generating light by usingoptical semiconductor devices and a lighting apparatus having the lightemitting module.

2. Discussion of the Background

Conventionally, an indoor lighting apparatus installed in a ceiling or awall of a house or an office adopts an incandescent light bulb or afluorescent lamp. However, the incandescent light bulb or thefluorescent lamp has demerits such as a short life time, low brightness,low energy efficiency, etc. Therefore, recently a lighting apparatusadopting light emitting diodes (LEDs) with relatively long life time,high brightness, high energy efficiency, etc. increases its marketshare.

The lighting apparatus with LEDs is widely used in applications such asa desk lamp, a flash lamp, or a surface lighting apparatus installed ina ceiling.

FIG. 1 is a schematic cross-sectional view illustrating a lightingapparatus, and FIG. 2 is a bottom view illustrating the lightingapparatus in FIG. 1.

A mother printed circuit board (PCB) may be separated into two PCBs 110,each of which has a body 111 and plurality of elbows 112. A plurality ofoptical semiconductors 120 may be disposed in a matrix shape on the PCB110. However, lengths of an output wiring connecting the opticalsemiconductors 120 may be different from each other. Therefore, voltagedrops of the output wiring may be different, and induce electric currentdeviation to cause brightness deviation among optical semiconductors120.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a light emittingmodule and a lighting apparatus, which are capable of eliminatingbrightness deviation among optical semiconductor devices.

A light emitting module according to an exemplary embodiment includes aprinted circuit board (PCB) and a first through an m-th lighting blocksof optical semiconductor devices (‘m’ is an integer greater than one).The PCB has wiring patterns for electric connection of opticalsemiconductor devices. The first through the m-th lighting block aredisposed on the PCB and generating light by provided electric power.Each of the first through the m-th lighting block comprises a firstthrough an n-th lighting group (‘n’ is an integer equal to or greaterthan one), each of which comprises a plurality of optical semiconductordevices disposed on the PCB Electric current is configured to flowthrough each of the first through n-th lighting groups is substantiallythe same. The PCB includes a pair of bodies spaced apart from each otherand ‘m’ number of elbows connecting the pair of bodies, and each elbowrespectively corresponds to the first through the m-th lighting blocks.

For this, the first through the n-th lighting group of the first throughthe m-th lighting blocks may be electrically connected with each otherin series.

The optical semiconductor devices in each of the first through the n-thlighting group of the first through the m-th lighting block may beelectrically connected with each other in parallel.

For example, a last lighting group of a (k−1)-th lighting block (‘k’ isan integer, and 2≦k≦m) may be electrically connected with a firstlighting group of a k-th lighting block in series.

For example, each of the lighting groups may include same number ofoptical semiconductor devices.

On the other hand, the PCB may include a plus connector and a minusconnector for proving the optical semiconductor devices with electricpower.

And a first lighting group of the first lighting block may beelectrically connected to the plus connector and the last lighting groupof the m-th lighting block is electrically connected to the minusconnector.

In this case, a last lighting group of an i-th elbow may be electricallyconnected to a last lighting group of an (i+1)-th elbow (‘i’ is an oddnumber smaller than ‘m’), and a first lighting group of j-th elbow maybe electrically connected to a first lighting group of an (j+1)-th elbow(‘j’ is an even number smaller than ‘m’).

The light emitting module also includes a base plate. The first throughm-th lighting blocks of optical semiconductor devices are arranged inlines to form optical semiconductor device rows.

The PCB may include openings that expose the base plate.

The openings of the PCB are between the optical semiconductor devicerows.

The openings of the PCB extend along a row direction Dl and the ‘m’elbows are spaced apart from each other by the openings of the PCB.

The number of openings of the PCB is smaller than the ‘m’ elbows by one.

According to the light emitting module and the lighting apparatus of thepresent invention, brightness deviation of the optical semiconductordevices is eliminated.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a schematic cross-sectional view illustrating a lightingapparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a bottom view illustrating the lighting apparatus in FIG. 1.

FIG. 3 is a circuit diagram illustrating an electrical connectionstructure of a x b number of optical semiconductor devices.

FIG. 4 is a bottom view illustrating an electrical connection structureof optical semiconductor devices on a PCB as shown in FIG. 2.

FIG. 5 is a bottom view illustrating an electrical connection structureof optical semiconductor devices on a PCB as shown in FIG. 2 accordingto an exemplary embodiment of the present invention.

FIG. 6 is a circuit diagram illustrating the electrical connectionstructure of the optical semiconductor devices in FIG. 4.

FIG. 7 is a circuit diagram illustrating the electrical connectionstructure of the optical semiconductor devices in FIG. 5.

FIG. 8 and FIG. 9 are circuit diagrams for showing the difference ofelectrical connection structures of the optical semiconductor devices inFIG. 4 and FIG. 5.

FIG. 10 is a bottom view illustrating an electrical connection structureof optical semiconductor devices according to another exemplaryembodiment of the present invention.

FIG. 11 and FIG. 12 are bottom views illustrating a lighting apparatusaccording to exemplary embodiments of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The present invention is described more fully hereinafter with referenceto the accompanying drawings, in which example embodiments of thepresent invention are shown. The present invention may, however, beembodied in many different forms and should not be construed as limitedto the example embodiments set forth herein. Rather, these exampleembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present invention tothose skilled in the art. In the drawings, the sizes and relative sizesof layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent invention. As used herein, the singular forms “a,” “an” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments of the invention are described herein with referenceto cross-sectional illustrations that are schematic illustrations ofidealized example embodiments (and intermediate structures) of thepresent invention. As such, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, example embodiments of thepresent invention should not be construed as limited to the particularshapes of regions illustrated herein but are to include deviations inshapes that result, for example, from manufacturing. For example, animplanted region illustrated as a rectangle will, typically, haverounded or curved features and/or a gradient of implant concentration atits edges rather than a binary change from implanted to non-implantedregion. Likewise, a buried region formed by implantation may result insome implantation in the region between the buried region and thesurface through which the implantation takes place. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the actual shape of a region of a device andare not intended to limit the scope of the present invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 2 is a bottom view illustrating a lighting apparatus according toan exemplary embodiment of the present invention.

Referring to FIG. 1 and FIG. 2, a lighting apparatus 100 according to anexemplary embodiment of the present invention includes a base plate 140and a light emitting module 160. Additionally, the lighting apparatus100 may further include a power supply 170 proving the light emittingmodule 160 with external electric power.

For example, the base plate 140 may have a rectangular shape. The baseplate 140 may be coated with a material with white color or silver colorto have high optical reflectivity. When the base plate 140 is coatedwith the material with white color and silver color, lighting efficiencymay be improved.

The light emitting module 160 includes a printed circuit board (PCB) 110and a plurality of optical semiconductor devices 120.

The PCB 110 is disposed on the base plate 140. An optical cover 150 maybe disposed over the PCB 110 and contacting the base plate 140.

The optical semiconductor devices 120 are arranged in a row direction D₁and in a column direction D₂ to be arranged in a matrix shape on the PCB110.

The PCB 110 has opening portions R between the optical semiconductor 120rows, so that the base plate 140 is exposed through the opening portionsR. In this case, the opening portions R may extend along the rowdirection D₁. Further the opening portions R may extend to a first endportion E₁ of the PCB 110.

In other words, the PCB 110 may have a body 111 and m number of elbows112 (‘m’ is an integer greater than one) integrally formed with the body111. The elbows 112 are spaced apart from each other with the opening R,and the elbows 112 and the openings R are alternately disposed. In thiscase, the number of the openings R is smaller than the m number ofelbows by one. The body 111 has a bar shape and is disposed adjacent toan edge portion. In detail the body 111 is disposed adjacent to a secondend portion E₂ that is opposite to the first end portion E₁. The mnumber of elbows 112 extend from the body 111 toward the first endportion E₁. As described above, the body 111 and the elbows 112 may bedivided by a vertical imaginary line A. However, when we define theelbows 112 having a bar shape, and the body 111 connects the elbows 112,the body 111 and the elbows 112 may be divided by a horizontal imaginaryline B.

In each of the elbows 112, optical semiconductor devices 120 arearranged in a line to form an optical semiconductor device row, and theopening portion R is a space between the elbows 112.

In FIG. 2, the row direction D₁ and the column direction D₂ areperpendicular to each other. However, the row direction D₁ and thecolumn direction D₂ may not be perpendicular to each other.

Further, the optical semiconductor devices 120 may be arranged in a linein each of the elbows 112 in FIG. 2. However, optical semiconductordevices 120 may be arranged in a plurality of lines in each of theelbows 112.

On the other hand, the PCB 110 is electrically connected through a pairof connectors 130 to provide the optical semiconductor devices 120 withexternal electric power. Therefore, according to the present invention,the number of the connectors 130 may be reduced to simplify a wiring andthe base plate 140 is exposed through the opening R to improve heatdissipation of the base plate 140.

Hereinafter, an electric connection structure of the opticalsemiconductor devices 120 arranged in a matrix shape will be explainedin detail.

FIG. 3 is a circuit diagram illustrating an electrical connectionstructure of a×b number of optical semiconductor devices.

In the optical semiconductor devices 120 arranged in a matrix shape inFIG. 2, a-number of optical semiconductor devices 120 are electricallyconnected in series, and b-number of groups in each of which thea-number of optical semiconductor devices 120 electrically connected inseries are electrically connected in parallel (hereinafter, thisstructure is referred to as ‘a-serial b-parallel’).

Through this electric connection structure, the power supply 170 in FIG.1 effectively provides electric power to the optical semiconductordevices arranged in a matrix shape.

The optical semiconductor devices 120 in FIG. 2 according to anexemplary embodiment of the present invention may be electricallyconnected as follows. That is, the optical semiconductor devices 120 inthe row direction may be divided into at least one lighting group, andoptical semiconductor devices 120 in the same group may be electricallyconnected with each other in parallel, and the lighting groups may beelectrically connected in series. That is, each of the m number ofelbows 112 includes n number of lighting groups, each of which includesthe same number of optical semiconductor devices 120 electricallyconnected with each other in parallel, and the n number of lightinggroups are electrically connected with each other in series.

In this case, a lighting group in an elbow 112, which is adjacent to thefirst end portion E₁ may be electrically connected with a lighting groupin a next elbow 112, which is adjacent to the second end portion E₂. Inother words, a last lighting group of a (k−1)-th lighting block (‘k’ isan integer, and 2≦k≦m) is electrically connected with a first lightinggroup of a k-th lighting block in series. In this case, a lighting groupin a first row or a first elbow, which is adjacent to the second endportion E₂ is electrically connected to a plus connector of the PCB 100,and a lighting group in a last row or a last elbow, which is adjacent tothe first end portion E₁ is electrically connected to a minus connectorof the PCB 100.

When the optical semiconductors 120 are connected as described above,electric currents flowing through each lighting group may besubstantially the same.

For example, a case in which the PCB 110 has three elbows and theoptical semiconductor devices 120 are connected with each other to have‘six serial three parallel’ structure will be explained in detailreferring to FIG. 4 and FIG. 5.

FIG. 4 is a bottom view illustrating an electrical connection structureof optical semiconductor devices on a PCB in FIG. 2, and FIG. 5 is abottom view illustrating an electrical connection structure of opticalsemiconductor devices on a PCB in FIG. 2 according to an exemplaryembodiment of the present invention.

When electric connection structure of ‘six serial three parallel’ isrequired, six optical semiconductors 120 in one row (or one elbow) maybe electrically connected with each other in series, and three lightinggroups N₁, N₂ and N₃ , each of which corresponds to each of elbows maybe electrically connected with each other in parallel as shown in FIG.4.

In detail, a first optical semiconductor device in each of the lightinggroups N₁, N₂ and N₃ of three elbows, which is adjacent to the secondend portion E₂, is electrically connected to the plus connector 131, anda last optical semiconductor device in each of the lighting groups

N₁, N₂ and N₃ of three elbows, which is adjacent to the first endportion E₁, is electrically connected to the minus connector 132.

On the other hand, in order to connect the last optical semiconductordevice in each of the lighting groups N₁, N₂ and N₃ of three elbows,which is adjacent to the first end portion E₁, to the minus connector132, there is no other way except for different wiring length.

In detail, the last optical semiconductor device of the third lightinggroup N₃ of the third elbow is electrically connected to the minusconnector 132 through a third wiring l₃.

On the other hand, the last optical semiconductor device of the secondlighting group N₂ of the second elbow requires a second wiring l₂ to beis electrically connected to the third wiring l₃. Therefore, the lastoptical semiconductor device of the second lighting group N₂ of thesecond elbow is electrically connected to the minus connector 132through the second wiring l₂ and the third wiring l₃. Therefore, theoutput wiring of the second lighting group N₂ of the second elbow islonger than the output wiring of the third lighting group N₃ of thethird elbow by the second wiring l₂.

Further, the last optical semiconductor device of the first lightinggroup N₁ of the first elbow requires a first wiring l₁ to beelectrically connected to the second wiring l₂. Therefore, the lastoptical semiconductor device of the first lighting group N₁ of the firstelbow is electrically connected to the minus connector 132 through thefirst wiring l₁, the second wiring l₂ and the third wiring l₃.Therefore, the output wiring of the first lighting group N₁ of the firstelbow is longer than the output wiring of the third lighting group N₃ ofthe third elbow by the first wiring l₁ and the second wiring l₂.

However, in order to connect the optical semiconductor devices 120 witheach other to have ‘six serial three parallel’ structure according to anexemplary embodiment of the present invention, the optical semiconductordevices 120 in each elbow N₁, N₂, N₃ are divided into two lightinggroups, and three optical semiconductor devices in each lighting groupare connected with each other in parallel. Then, eighteen opticalsemiconductor devices are divided into six lighting groups G₁, G₂, . . ., G₆, and the six lighting groups G₁, G₂, . . . , G₆ are connected witheach other in series.

And the first optical semiconductor device in the first group G₁, whichis adjacent to the second end portion E₂, is electrically connected tothe plus connector 131, and the last semiconductor device in the lastgroup G₆, which is adjacent to the first end portion E₁, is electricallyconnected to the minus connector 132.

The wiring structure in FIG. 5 may be simply express as a circuitdiagram in FIG.

7. As shown in FIG. 7, the electric connection structure of the opticalsemiconductor devices in FIG. 7 is ‘six serial three parallel’ as inFIG. 6.

FIG. 8 and FIG. 9 are circuit diagrams for showing the difference ofelectrical connection structures of the optical semiconductor devices inFIG. 4 and FIG. 5.

In FIG. 8, the output wiring of a first lighting group G₁ has a firstlength L₁ and the output wiring of a second lighting group G₂ has asecond length L₂ that is different from the first length L₁. On theother hand, the output wiring of a first lighting group G₁ and theoutput wiring of a second lighting group G₂ have the same length L₁ andL₂ in FIG. 9.

In real cases, the wiring has electric resistivity. Therefore, when thelength of wiring increases, the electric resistance also increases.Therefore, the electric current flowing through the first lighting groupG₁ is different from the electric current flowing through the secondlighting group G₂.

In detail, the electric current flowing through the first lighting groupG₁ which has relatively high electric resistance, is relatively smallerthan the electric current flowing through the second lighting group G₂,since the voltage drop of first lighting group G₁, which is generatedbetween the last optical semiconductor and the minus connector isgreater than the voltage drop of second lighting group G₂, which isgenerated between the last optical semiconductor and the minusconnector. As a result, the brightness of the optical semiconductors inthe first lighting group G₁ is lower than the brightness of the opticalsemiconductors in the second lighting group

G₂.

That is, the optical semiconductor devices of the lighting groups N₁, N₂and N₃ of each elbow in FIG. 4 have different brightness with eachother, but the optical semiconductor devices of the lighting groups G₁,G₂, . . . , G₆ in FIG. 5 have same brightness.

FIG. 10 is a bottom view illustrating an electrical connection structureof optical semiconductor devices according to another exemplaryembodiment of the present invention. The light emitting module of thepresent embodiment is substantially the same as that in FIG. 5 exceptfor a shape of PCB and wiring patterns formed on the PCB. Thus, anyrepetitive explanation will be omitted.

Referring to FIG. 10, a PCB 110 according to another exemplaryembodiment of the present invention has opening portion R disposedbetween rows of optical semiconductor devices 120, and a base plate 140is exposed through the opening portion R. In this case, the openingportion R may extend along the row direction. However, the openingportion R does not reach a first end portion E₁ unlike the openingportion R of the PCB 110 in FIG. 5.

In other words, the PCB 110 has a pair of bodies 111 and a plurality ofelbows 112. The pair of bodies 111 has a bar shape disposed at the firstand second end portions E₁ and E₂, respectively. The plurality of elbows112 connects the pair of bodies 111.

Each of the elbows 112 has optical semiconductors 120 arranged in a lineto form optical semiconductor device row, and the opening portion R isdisposed between the optical semiconductor device row.

The optical semiconductor devices 120 of a row is divided at least onelighting group, and the optical semiconductor device 120 in a samelighting group are electrically connected with each other in parallel,and the lighting groups are connected with each other in series. In thiscase, a lighting group of a row, which a disposed adjacent to the firstend portion E₁ is electrically connected to a lighting group of a nextrow, which is disposed adjacent to the first end portion E₁, and alighting group of a row, which a disposed adjacent to the second endportion E₂ is electrically connected to a lighting group of a next row,which is disposed adjacent to the second end portion E₂.

In detail, a last lighting group of an i-th elbow is electricallyconnected to a last lighting group of an (i+1)-th elbow (‘i’ is an oddnumber smaller than m), and a first lighting group of j-th elbow iselectrically connected to a first lighting group of an (j+1)-th elbow (Tis an even number smaller than m). In this case, the first lightinggroup means the lighting group disposed adjacent to the second endportion E₂, and the last lighting group means the light group disposedadjacent to the first end portion E₁.

For example, the second lighting group G₂ of a first row, which isadjacent to the first end portion E₁, is electrically connected to thefourth lighting group G₂ of a second row, which is adjacent to the firstend portion E₁ through wiring B₁ formed at the body 111 with the firstend portion E₁. The third lighting group G₃ of the second row, which isadjacent to the second end portion E₂, is electrically connected to thefifth lighting group G₅ of a third row, which is adjacent to the secondend portion E₂ through wiring B₂ formed at the body 111 with the secondend portion E₂.

On the other hand, the first lighting group G₁, which is adjacent to thesecond end portion E₂ is also electrically connected to the plusconnector 131 of the PCB 110, and the last lighting group of last row,which is adjacent to the first end portion E₁ or the second end portionE₂, is also electrically connected to the minus connector 132.

In detail, when the number of elbow is odd number, the lighting group ofthe last row, which is adjacent to the first end portion E₁, iselectrically connected to the minus connector 132. On the contrary, whenthe number of elbow is even number, the lighting group of the last row,which is adjacent to the second end portion E₂, is electricallyconnected to the minus connector 132.

Comparing the light emitting module of the present embodiment with thelight emitting module in FIG. 5, the light emitting module hasrelatively longer wiring length, so that the voltage drop between thelast optical semiconductor device and the minus connector becomesrelatively greater, so that electric currents is reduced relatively moreto lower the brightness relatively more, but the light emitting modulehas relatively shorter wiring length, so that the voltage drop betweenthe last optical semiconductor device and the minus connector becomesrelatively smaller, so that electric currents is reduced relativelylittle to lower the brightness relatively little.

FIG. 11 and FIG. 12 are bottom views illustrating a lighting apparatusaccording to exemplary embodiments of the present invention.

The lighting apparatus of the present exemplary embodiments issubstantially same as the lighting apparatus of the previous embodimentsexcept for light emitting module and arrangement thereof. Thus, anyrepetitive explanation will be omitted.

Referring to FIG. 11 and FIG. 12, the lighting apparatus of presentexemplary embodiments includes a plurality of light emitting modules. Inthis case, the light emitting modules may be arranged such that bodiesof the light emitting modules are adjacent to each other as shown inFIG. 11. However, the light emitting modules may be arranged such thatelbows of the light emitting modules are adjacent to each other as shownin FIG. 12.

When the light emitting modules are arranged as shown in FIG. 11, theconnector 130 may be formed at the body, and the light emitting modulesare arranged as shown in FIG. 12, the connector 130 may be formed at theelbow.

The exemplary embodiments shown in FIG. 11 and FIG. 12 may be modifiedas described above with reference to the exemplary embodiments describedin FIG. 5 to FIG. 10.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A light emitting module, comprising: a printedcircuit board (PCB) comprising wiring patterns electrically connectingoptical semiconductor devices; and first through m-th lighting blocks ofoptical semiconductor devices disposed on the PCB and configured togenerate light, wherein ‘m’ is an integer greater than one, wherein eachof the first through the m-th lighting blocks comprises first throughn-th lighting groups, wherein each block comprises at least one group,each of the first through n-th lighting groups comprises opticalsemiconductor devices disposed on the PCB, and an electric currentconfigured to flow through each of the first through n-th lighting groupis substantially the same, and wherein the PCB comprises a pair ofbodies spaced apart from each other and ‘m’ number of elbows connectingthe pair of bodies, and each elbow respectively corresponds to the firstthrough the m-th lighting blocks.
 2. The light emitting module of claim1, wherein the first through the n-th lighting groups of each of thefirst through the m-th lighting blocks are electrically connected witheach other in series.
 3. The light emitting module of claim 1, whereinthe optical semiconductor devices in each of the first through the n-thlighting groups of each of the first through the m-th lighting blocksare electrically connected with each other in parallel.
 4. The lightemitting module of claim 2, wherein a last lighting group of a (k−1)-thlighting block, wherein ‘k’ is an integer, and 2≦k≦m, is electricallyconnected with a first lighting group of a k-th lighting block inseries.
 5. The light emitting module of claim 1, wherein each of thelighting groups comprises the same number of optical semiconductordevices.
 6. The light emitting module of claim 1, wherein the PCBcomprises a plus connector and a minus connector configured to providethe optical semiconductor devices with electric power.
 7. The lightemitting module of claim 6, wherein a first lighting group of the firstlighting block is electrically connected to the plus connector and alast lighting group of the m-th lighting block is electrically connectedto the minus connector.
 8. The light emitting block of claim 1, whereina last lighting group of an i-th elbow is electrically connected to alast lighting group of an (i+1)-th elbow, wherein ‘i’ is an odd numbersmaller than ‘m’, and a first lighting group of j-th elbow iselectrically connected to a first lighting group of an (j+1)-th elbow,wherein ‘j’ is an even number smaller than ‘m’.
 9. The light emittingblock of claim 1, further comprising a base plate, wherein the firstthrough m-th lighting blocks of optical semiconductor devices arearranged in lines to form optical semiconductor device rows.
 10. Thelight emitting block of claim 9, wherein the PCB further comprisesopenings that expose the base plate.
 11. The light emitting block ofclaim 10, wherein the openings of the PCB are disposed between theoptical semiconductor device rows.
 12. The light emitting block of claim11, wherein the openings of the PCB extend along a row direction and the‘m’ elbows are spaced apart from each other by the openings of the PCB.13. The light emitting block of claim 12, wherein the number of openingsof the PCB is smaller than the ‘m’ elbows by one.